Page 39 - Breeding Edge ebook

On an even larger scale, using a gene drive on another strain of mosquito – the top malaria-spreading
one -- might save millions of people in Africa and Asia from illness and death. More than 200 million
people get the parasitic disease annually, and nearly half a million die from it, according to the World
Malaria Report 2017.

Years ago, UC, Irvine biologist Anthony James found specific genes in Anopheles gambiae, a type of
mosquito, that pass malaria-resistance on to offspring. Those with the trait can carry the disease but are
not able to spread it. More recently, he and fellow scientists have been funded to develop a gene drive to
spread that resistance to all offspring of that strain of mosquito.

Field testing a malaria mosquito gene drive will probably occur in Africa, where malaria is by far the
most prevalent. But James tells Agri-Pulse that it is “hard to predict” when it will start or in which
countries.

“There are significant scientific, regulatory and social challenges to be met” before breeding such
mosquitoes in the open, he says. He notes that the hosting countries will have to approve the work.

What’s more, scientists at Imperial College London have prepared their own mosquito gene drive: this
one to impose infertility on female offspring of the same malaria mosquitoes.

As with most biotech advances, there is fear about possible outcomes, especially, in this case, runaway
unintended results in the wild.

The Broad Institute of the Massachusetts Institute of Technology and Harvard, which hold the patent for
CRISPR-Cas9, discourage its use for gene drives. Also, a year ago, environmental advocates pressed
world governments at their meeting as the United Nations Convention on Biodiversity, to initiate a ban
on gene drives. Scientists there persuaded the gathering to reject that move, but the technology will
undoubtedly face a lot of opposition worldwide.

Ryan Phelan, a wildlife conservationist and executive director

of Revive & Restore, agreed at the UC-Davis, CRISPR conference that
the gene drive concept “does bring up huge issues” when it comes to
protecting wildlife, especially threatened species. She asks: “Who gets
to decide how you adopt something that knows no bounds?”

Yet, she says, in trying to protect wildlife, “there are some
problems that are so intractable,” and she thinks gene editing may
have to be one of the remedies pursued while mankind still has an

opportunity to try solutions.

Ryan Phelan, a wildlife Phelan points, for instance, to an invasive strain of mosquito in Hawaii
conservationist and executive
director of Revive and Restore that spreads avian malaria, which has already killed off some wild
species of birds there and threatens the survival of others, including the

native honeycreeper. Plus, the impact on the birds is worsening as

climate change brings higher temperatures – and more avian malaria mosquitoes – into Hawaiian

mountain habitat.

“Gene drive could indeed be part of an ultimate solution,” Phelan opines. “But gene drive technology
needs more iterations before we could safely test gene drives in the wild,” and she says, and applying the

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